Yb-doped borate-silicate glasses with various Yb2O3 concentrations were fabricated by means of high-temperature solid-state reaction. The absorption and the photoluminescence, as well as the Raman spectra, were measured and analyzed. The absorption and emission cross-section around 980nm is calculated based on the absorption measurement. The dependence of radiative lifetime of Yb3+-2F5/2 on Yb2O3 concentration is also presented. The relationship between up-conversion photon and the infrared emission, together with the assistant phonon, is described according to the up-conversion photoluminescence and Raman spectra analysis.